I thought I read that the tag itself will start beeping if it's not near its owner for too long, and the tag has been moving around? Not sure what "too long" means, but if it's short enough, that should foil stalking attempts if the potential stalkee doesn't have an iDevice.

Edit: looks like it doesn't start beeping for three days (though Apple can change this server-side if they decide three days was a bad choice), which seems like way too long. A stalker could probably make good use of this in just a few hours, let alone three days.